What is Vacuum Metalizing?
Vacuum metalizing is a process that allows you to create a layer of metal on a substrate, usually of another material. Also referred to as “vacuum deposition”, it involves heating the metal coating material until it vaporizes inside a vacuum chamber.
The lack of pressure in this chamber drives the metal’s boiling point downward. This allows the metal vapor to condensate and form a layer over the top of a substrate of your choice. For example, the semiconductor industry uses vacuum deposition to deposit copper interconnects on silicon.
The process may use various heating methods, including plasma beams, resistance heating, and electron beams. The end result is a metal layer that can range in thickness from a single atom through to several millimeters.
Typically, the metalizing occurs in one of two ways:
- Physical Vapor Deposition: The metal vapor used for the coating comes from a liquid or solid source.
- Chemical Vapor Deposition: The metal vapor comes from a chemical source.
Both processes follow the same steps.
Step 1 – Tooling
We fabricate customized tooling fixtures, which hold your parts in place ready for masking. The key here is to drive efficiency at all stages of the tooling process. Poor tooling drives up costs later on.
At the tooling stage, we create an array that achieves maximum coverage of your parts. As a general rule, we create lower costs by coating more parts per cycle.
Step 2 – Loading
We follow strict loading procedures to lower the risk of contamination and defects during the metalizing process. Our quality guidelines consider your quality standards as the minimum standard we must achieve. Typically, we’ll look to exceed these quality standards wherever possible.
We also use pre-masking procedures during the loading process. This reduces the need for manual masking later on. Again, this reduces the cost of the process.
Step 3 – Applying the Base Coating
Though not always necessary, this step primes the part so that it can properly receive the metal vapor. A base coating improves the adhesive quality of the part. This leads to longer-lasting results.
We use a High-Volume, Low-Pressure Spray System to apply the coating. The process itself depends on the parts that require coating. We use automated robotic paint arms for high-volume applications. However, low-volume applications often see the base coating applied manually.
Step 4 – Vacuum Metalizing
Using a vacuum chamber, we vaporize the metal using a filament. This vapor flows in a single direction, which offers our equipment full control over its flow onto a part.
The machine rotates the part precisely to ensure even deposition of the metal vapor. This creates a consistent coating thickness. This is also where the tooling used in Step 1 comes into practice. This tooling ensures the parts stay in place through the metalizing process.
Step 5 – Applying the Top Coat
Though not always required, a top coat can enhance the properties of your coated part. For example, some coatings improve the part’s chemical, moisture, or abrasion resistance.
In some cases, a top coating can enhance the appearance of the part.
Typically, we’ll recommend a top coating if our review of your requirements calls for it. We also engineer this coating to suit your requirements.
Step 6 – Quality Inspection
All parts undergo rigorous quality inspections before they’re released to the client.
These inspections ensure the part exceeds current industry standards. Moreover, they ensure the part meets or exceeds the specific requirements that you put in place. Such requirements may include ensuring the part meets the following standards:
- ISO 9001
- ISO/TS 16949
Moreover, we track errors throughout the process to ensure they’re corrected. Each part comes with a tracking tag for further traceability.
The Benefits Of Vacuum Metallizing
Vacuum metalizing use has grown in recent years for several reasons. These include the following:
- It provides the aesthetic appeal of metal parts while lowering the cost.
- It’s safer than other processes, such as chrome plating. Vacuum metalizing does not require the dangerous mixing of chromium with cyanide.
- The purer process reduces the risk of chemicals in the part causing issues for people.
- It offers higher levels of resilience than other forms of metal coating.
What are the Uses of Vacuum Metalizing?
Vacuum Metalizing has many uses. These include, but are not limited to, the following:
- The creation of decorative metallic finishes
- Reflective coatings
- Vapor barriers
- EMI shielding
- Heat shielding
What’s the Environmental Impact?
Practically nil. Vacuum metalizing is a self-contained process that takes place almost entirely in the vacuum chamber. This ensures that metal vapors do not get released into the air.
What’s the Best Metal for the Process?
Most agree on aluminum being the best metal for vacuum metalizing. Only silver and copper offer higher conductivity. Silver drives up the cost of the process, whereas copper often suffers from oxidation and corrosion.
By contrast, aluminum forms an oxide layer that protects against corrosion and doesn’t cause issues with electrical contact.
To inquire about vacuum metalizing, call us for a free consultation on (603) 769-3487. Alternatively, contact us via our website to discuss your requirements.